1. Industrial Fieald of the Invention
The present invention relates to a stacker for stacking food loaf slices for use in a food slicing machine.
2. Prior Art
Recently it has become not unusual that food loaf products, such as, for example, ham loaf products, are vacuum packaged in sliced condition and sold in the form of a packaged product at food stores, food floors of super markets, and the like retail outlets.
Such packaged form of sliced ham products is broadly classified into two, namely, one in which a given number of ham slices (N slices), each of a predetermined thickness, are packaged in stacked condition as such, and the other in which N slices of ham are packaged in overlapping fashion, one over another.
These two types of packaged ham products are commercially produced as such by slicing ham loaves by a ham slicing machine in a ham producer's germ-free room, then packing ham slices so produced into packages by a packaging machine. In the ham producer's factory, it is required that a large number of ham loaves be sliced as efficiently as possible and that these ham loaf slices be packed into packaged products in sanitary manner and with the least possible chance of human hand touching the ham slices.
To this end, a number of movable stackers for use in food loaf slicing machines for slicing an elongate food loaf, such as ham loaf, into slices of a predetermined thickness have been developed which are of the type that a predetermined number of food loaf slices are received on the stacker as they are dropped from a slicing station, with no chance of the slices being touched by hand, so that a stack of slices is formed on the stacker, the stack being then moved to a position at which it has no chance to interfere with a next cycle of receiving slices as they drop on the stacker. For example, disclosures relating to such stacker are found in U.S. Pat. No. 4,405,186 and U.S. Pat. No. 3,824,885.
Now, a ham loaf, in its form prior to being sliced, generally has a circular or quadrangular sectional configuration of 600-1600 mm in length and 90-100 mm in diameter. Normally, in known ham slicing machines, a ham loaf of such configuration, set upright or in a slightly inclined condition, is fed downwardly at a constant speed while being held between a pair of conveyors arranged in opposed relation in the longitudinal direction of the ham loaf, and the ham loaf delivered into the slicing station of the ham slicing machine is cut by a cutter rotating at a constant speed into slices of a predetermined thickness from its lower end.
Therefore, if ham loaf slices as cut by such a ham slicing machine are to be stacked on a stack support (such as, for example, receiver plate, receiver comb, or conveyor) without any horizontal irregularity, that is, if ham loaf slices are to be stacked upright on the stack support while exhibiting virtually same appearance as the original ham loaf, it is essential that the distance between the front end of the cutter and the position at which the falling movement of each ham slice ends should be always constant.
In the above cited prior-art arrangements, therefore, stack supports are movable upward and downward so that each time a food loaf slice drops on one of the stack supports, the stack support is lowered a distance corresponding to the thickness of one slice, whereby the distance of slice dropping is always kept constant.
With such stack support arrangement, however, it is necessary that when a stack of N slices is formed on the stack support in such way as above mentioned, the stack must be transported to a location outside the slice dropping position so as for it not to interfere with a next cycle of stack forming. Further, if the ham slicing machine is continuously operated in order to maintain a constant slice thickness, and if the machine is run at high speed in order to obtain increased efficiency, each stack of slices, as it is formed, must be promptly moved away from the slice dropping position while the cutter is in the course of one rotation, that is, within one slice cycle of the cutter.
To this end, the stackers disclosed in aforesaid U.S. Pat. No. 3,824,885 and U.S. Pat. No. 4,405,186 are of such arrangement that when a stack of slices is formed on one stack support, the stack support is rapidly moved downward and another stack support is brought to an initial slice receiving position.